Dear Colleagues, Journal* Sustainability* (ISSN 2071-1050; IF 3.251) is currently running a Special Issue entitled “*Sustainable Conservation of Marine Mammals: Latest Advances and Prospects*". We invite you to contribute to this Special Issue with a comprehensive *R**eview* paper or full *O**riginal **R**esearch **A* *rticle* reporting the latest experimental and theoretical research progress with high quality results from your group. For further reading, please follow the link to the Special Issue Website at: https://www.mdpi.com/journal/sustainability/special_issues/marine_mammals_co... The submission deadline is *30 April 2022*. You may send your manuscript now or up until the deadline. Submitted papers should not be under consideration for publication elsewhere. We also encourage authors to send a short abstract or tentative title to the Editorial Office in advance ( sustainability@mdpi.com). *Sustainability* is a fully open access journal. Open access (unlimited and free access by readers) increases publicity and promotes more frequent citations, as indicated by several studies. Open access is supported by the authors and their institutes. For further details on the submission process, please see the instructions for authors at the journal website ( https://www.mdpi.com/journal/sustainability/instructions). We look forward to hearing from you. Kind regards, Dr. Patricia Arranz *Guest Editor*